(HealthDay News) — In patients with metastatic hormone-sensitive prostate cancer, intermittent androgen deprivation is associated with slightly, but not significantly, worse survival than continuous androgen deprivation, according to a study published in the April 4 issue of the New England Journal of Medicine.

Maha Hussain, M.D., from the University of Michigan in Ann Arbor, and colleagues analyzed data from 1,535 men with metastatic hormone-sensitive prostate cancer who had been receiving a luteinizing hormone-releasing hormone analog and an antiandrogen agent for seven months. If prostate-specific antigen levels fell to 4 ng per milliliter or lower after treatment, the men were randomly assigned to continuous or intermittent androgen deprivation.

After a median follow up of 9.8 years, the researchers found that median survival was lower for the intermittent therapy group (5.1 versus 5.8 years, hazard ratio 1.10, 90% confidence interval, 0.99 to 1.23). Erectile function and mental health were significantly better after intermittent therapy, but only at 3 months. The two groups had similar numbers of treatment-related high-grade adverse events.

“In patients with metastatic hormone-sensitive prostate cancer, the confidence interval for survival exceeded the upper boundary for noninferiority, suggesting that we cannot rule out a 20% greater risk of death with intermittent therapy than with continuous therapy, but too few events occurred to rule out significant inferiority of intermittent therapy,” Hussain and colleagues conclude.